Author: (Garman, 1906)
Field Marks:
A small slender shark with a rounded, moderately long snout, large lateral eyes with nictitating eyelids, small spiracles, moderate-sized gill slits about 1.3 times eye length in adults (less in young), rather short arched mouth with upper labial furrows reaching anteriorly to symphyses of jaws, lower teeth not prominently protruding, upper teeth with distal cusplets but no serrations, lower anterior teeth with moderately long, nearly straight smooth-edged cusps, lateral teeth with prominent cusplets and mostly oblique cusps, roots of lower teeth not strongly arched, anterior teeth T shaped, two spineless dorsal fins and an anal fin, second dorsal about 2/ 3 size of first, second dorsal origin slightly ahead of anal origin, anal fin smaller than second dorsal and without preanal ridges, transverse, crescentic precaudal pits, and light grey or bronze colour with longitudinal yellow bands on the body (not prominent in preserved specimens) and light posterior fin margins.
Diagnostic Features:
Upper labial furrows reaching anteriorly to upper symphysis; lower anterior and lateral teeth with prominent cusplets present on distal and (especially in anterior teeth) mesial crown feet; lateral teeth with mostly oblique cusps. Caudal vertebral centra 62 to 73, total vertebral counts 135 to 149.
Geographical Distribution:
Eastern Atlantic: Cape Verde Islands and Mauritania to Angola, possibly northward to Morocco. ?Western North Atlantic: New England (see remarks below).
Habitat and Biology:
A very common inshore to offshore shark of the continental shelf of tropical and warm-temperate West and northwest Africa, inshore to offshore from a few metres to slightly over 100 m.
Viviparous, with a yolk-sac placenta; number of young per litter 1 to 4 but mostly (60% of 77 individuals) 2. Off Senegal most young are born in May and June.
As with Hemigaleus microstoma (or a close relative) off Australia, this species apparently is a specialist feeder that prefers cephalopods, including squid and octopi. Of a large number examined off Senegal 90% had cephalopods in their stomachs (Cadenat and Blache, l9B2). The remainder of this species' diet is comprised of small bony fishes, including soles and sardines.
Size:
Maximum 138 cm; males mature at about 80 cm, with adult males reported from 76 to 114 cm; females mature between 75 and 90 cm, with adult females reported from 83 to 117 cm; size at birth about 47 cm.
Interest to Fisheries:
A common catch of artisanal and small commercial fisheries in the eastern Atlantic, but also taken by offshore international fisheries. It is caught on longlines, hook-and-line, gillnets, and bottom trawls; its meat is used fresh and dried salted for human consumption, and it is processed into fishmeal.
Remarks:
P. gruveli is considered a synonym of P. pectoralis, following Krefft (1968), Compagno (1979), and Cadenat and Blache (1982). The record of the holotype of this species from off New England may have been based on a waif that had crossed the Atlantic on the North Equatorial Current and rode the Gulf Stream up to where it was captured, since no further records of it have been reported from anywhere in the tropical western Atlantic. As probably suitable tropical habitat exists for this shark in the western Atlantic and such habitat has been extensively surveyed, the chances that a common, wide-ranging eastern Atlantic shark such as this species has an undiscovered cryptic population in the western Atlantic are limited. Another possibility is that the locality data for the specimen as obtained by Garman is erroneous. It seems unlikely that the shark was transported alive from the eastern Atlantic by human agency to the "Aquarial Gardens", because of the slow transportation (steamships) and limited aquarial technology available at the turn of the century.
Type material:
Holotype: Museum of Comparative Zoology, Harvard University, MCZ-847, 651 mm female. Type Locality: "...from the 'Aquarial Gardens', for which the collections were made off the coasts of Massachusetts and Rhode Island." (Garman, 1906).